suppositive

adj.
Of the nature of, including, or involving supposition.

n. Grammar
A conjunction, such as if or providing, that introduces a supposition.

suppositively sup·pos'i·tive·ly adv.

adjective

Presumed to be true, real, or genuine, especially on inconclusive grounds: conjectural, hypothetic, hypothetical, inferential, presumptive, supposed, suppositional, suppositious, supposititious. See belief/unbelief.